JPH06218766A - Color separation molding method - Google Patents

Abstract

PURPOSE:To reduce the cost of a different-color integrated molded form by a method wherein different-colored synthetic resins are injected respectively from a first injection unit, having an axial line in a direction coinciding with the center of a molding machine, and a second injection unit, having the axial line thereof in an orthogonal direction to the center of the machine and arranged at the side of the molding machine. CONSTITUTION:When the fixed mold 25 of a molding machine and a movable mold 12 of the same are clamped, synthetic resin is injected into a molding projection 12a, formed in the movable mold 12, and a molding space 47, formed in the fixed mold 25, through a first injection unit 20. The first injection unit 20 is formed so that the axial line thereof coincides with the center of the molding machine 1 of the first injection unit 20. The second injection unit 31, having the axial line thereof orthogonal to the center of the machine, is arranged at the side surface of the molding unit of the molding machine and resins, having different colors, are injected while abutting an injection nozzle 31a against a second spool 25c of the mating surface of the molds 12, 25. The injected synthetic resins, having two kinds of colors, are joined at the intermediate part of the molding space 47. Accordingly, different color molded form can be obtained inexpensively by arranging the second injection unit at the side of the injection molding machine so far.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor molding method for a molded product which is color-coded in different colors and integrally molded, or a molded product which is integrally molded with different kinds of synthetic resins.

[0002]

2. Description of the Related Art For example, in a container (product) containing parts, in order to easily confirm whether or not the parts are contained in the container, the left side and the right side are integrally molded with different color synthetic resins. When the parts are stored in the container, it is possible to stack them so that the right and left colors of each container are staggered in the vertical direction. Is configured to be stacked so that the colors of each container are continuous in the vertical direction.

As a conventional multicolor molding method for integrally molding products with synthetic resins of different colors or types, for example, as shown in Japanese Utility Model Publication No. Sho 63-27307, molten resin is injected from nozzles of a plurality of injection molding machines. A fixed-side mold plate having a plurality of sprues for introducing the movable mold plate, a movable-side mold plate arranged so as to come in contact with and separated from the fixed-side mold plate, and capable of appearing and retracting in a cavity formed by both mold plates. Each nozzle is provided with a two-color injection molding die including a partition member provided to partition the inside of the cavity into required spaces, and a drive cylinder provided in the movable mold plate to drive the partition member. Molded products are integrally molded by injecting synthetic resins of different colors or different types.

As another multi-color molding method, for example, as shown in Japanese Patent Publication No. 54-3489, a two-color injection molding nozzle has an inner cylinder nozzle having a needle opening / closing nozzle structure. A valve mechanism capable of slidingly projectingly fitting into the outer cylinder nozzle, providing a valve seat inside the outer cylinder nozzle tip injection port, and moving sideways with the inner cylinder nozzle tip part to block the outer passage. Using a two-color injection molding nozzle that has been formed, the synthetic resin of different colors or types is alternately injected with each nozzle being selectively opened and closed by moving the needle to form a molded product with different synthetic resin. It is integrally molded.

[0005]

However, in the former case, it is necessary to provide two injection devices in the main body of the molding machine in parallel with the center of the machine, and the molding machine itself is a dedicated machine to increase the cost. As a result, there is a problem that the molding cost becomes high.

In this special-purpose molding machine, one-color molding can be performed by using one injection device that is deviated from the machine center, but the injected synthetic resin goes from one side to the other side. Since it flows and molds over a long distance, there is a problem that the flow of the synthetic resin in the molding space changes subtly and molding defects easily occur.

In the latter case, it is necessary to provide a valve mechanism at the tip of each nozzle, which complicates the structure and increases the cost of the molding machine itself by making it a dedicated machine, resulting in a high molding cost. There is.

Further, when integrally molding molded articles of different colors of synthetic resins, the respective synthetic resins cannot be injected at the same time, so that the boundary portions where the respective synthetic resins of the respective colors merge are discontinuous, or the merging portion However, there is a problem in that the degree of color mixing in the case becomes large and the appearance becomes poor.

The present invention has been invented to solve the above-mentioned conventional drawbacks, and an object thereof is to provide a second injection unit in a conventional molding machine without using a dedicated molding machine. To provide a multicolor molding method capable of integrally molding a molded product with different colors or types of synthetic resins by arranging, and avoiding the high cost of the molding machine and reducing the molding cost. It is in.

Another object of the present invention is to provide a multicolor molding method capable of integrally molding a molded product having a good appearance by reducing the degree of color mixing at a boundary portion where synthetic resins of different colors or types merge. To do.

[0011]

Therefore, according to the present invention, there is provided a first mold having an axis in a direction coinciding with a machine center of a molding machine with respect to molding spaces of a fixed mold and a movable mold which are clamped. A second synthetic resin different from the first synthetic resin is provided by the second injection unit having an axis in the direction in which the first synthetic resin coincides with the machine center by the injection unit and in the direction orthogonal to the machine center. It is characterized in that the color-coded molded products are integrally molded by injecting each at a predetermined timing and injection pressure from a direction orthogonal to the machine center.

[0012]

Since the present invention comprises the above-mentioned method, the first synthetic resin is arranged from the first injection unit having the axis in the direction coinciding with the machine center of the molding machine, and is arranged on the side of the molding machine. Then, the second synthetic resin different from the first synthetic resin can be respectively injected from the second injection unit having the axis in the direction orthogonal to the machine center to integrally form the molded product.

Thus, one injection unit having two injection units or two injection cylinders each having an axis in a direction coinciding with the machine center and having a valve mechanism for switching the injection paths at the tip thereof is provided. Molded products can be integrally molded with a desired color or type of synthetic resin without using a fixed multicolor molding machine, and the molding cost can be reduced by lowering the cost of the molding machine itself. You can

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an example of an apparatus embodying the multicolor molding method.

FIG. 2 is a schematic cross-sectional view of the center of the separated dies.

The body side frame 3 of the molding machine 1 is provided with a fixed side mounting board 5 and a support frame 7 so as to face each other with a predetermined gap, and the fixed side mounting board 5 and the support frame 7 are provided with 4 units. A book tie bar 9 is provided at a diagonal position in parallel with the machine center of the main body frame 3. A movable side mounting board 11 is supported by the tie bar 9 so as to be movable in the axial direction, and a mold clamping cylinder 13 mounted on the movable side of the main body frame 3 is connected to a central portion of the movable side mounting board 11. . A movable mold 12 is attached to the center of the movable side mounting board 11, and the movable mold 12
A molding projection 12a is formed on the inner surface of the container 33.

A first injection device 15 is attached to the main body frame 3 on the fixed side so as to be movable and controllable in a direction orthogonal to the machine center of the main body frame 3.

That is, a pair of rails 17 are attached to the main body frame 3 on the fixed side in a direction orthogonal to the machine center, and a mounting base 19 is movably supported on the rails 17. The first injection unit 20 is attached to the mount 19 by the hydraulic cylinder 22 and the main body frame 3
It is mounted so that it can move in the direction that coincides with the machine center. Then, the first injection unit 20 injects a synthetic resin colored in a desired color as the first synthetic resin.

Further, the mounting table 19 has an axis in a direction orthogonal to the machine center, and a feed screw (neither is shown) connected to an electric motor is meshed with it, and as the feed screw rotates. The mount 19 is controlled to move in a direction orthogonal to the machine center.

The tip of the injection nozzle 20a is inserted into a horizontally elongated slide hole 5a formed in the fixed side mounting board 5 so as to be movable in a direction orthogonal to the machine center of the body frame 3. A fixed mold 25 is attached to the fixed-side mounting board 5, and a molding recess 25a that substantially matches the outer surface shape of a container 33 as a molded product shown in FIG. 4 is formed in the center of the fixed mold 25. There is.

A first sprue 25b is formed at one end of the molding recess 25a in a direction coinciding with the machine center of the body frame 3. A second sprue 25c is formed on the mold matching surface of the fixed mold 25 so as to be orthogonal to the machine center of the main body frame 3 and continuous with the other end of the container 33.

A second injection device 27 is arranged beside the molding section of the molding machine 1 in a state having an axis in a direction orthogonal to the machine center of the main body frame 3. That is, the second injection unit 31 is attached to the injection table 29 of the second injection device 27.
However, the position where the movable mold 12 and the fixed mold 25, whose tip ends of the injection nozzle 31a are clamped by the hydraulic cylinder 32, comes into contact with the second sprue 25c on the mating surface (parting surface) and is separated from the position. Mounted movably in between,
The second injection unit 31 injects a synthetic resin colored as a color different from the synthetic resin injected from the first injection unit 20 as the second synthetic resin.

Next, a multicolor molding method by the molding machine 1 configured as described above will be described.

FIG. 3 is a perspective view showing a molded product.

FIG. 4 is a schematic sectional view showing a multicolor molding state.

The container 33 as a molded product is formed in a box shape having a bottom and an open upper surface, and first engaging projections 37 extending vertically are integrally formed on the outer surfaces of both end portions of one short side plate 35. Has been done. Further, on the outer surface of the other short side plate 39, there are provided second engaging protrusions 41 extending in the vertical direction from the respective ends to the first
Are integrally formed at locations separated by the lateral width of the engaging projection 37. Then, engagement recesses 43 and 45 extending in the vertical direction are formed on the inner surfaces of the short side plates 35 and 39 of the first engagement protrusion 37 and the second engagement protrusion 41, respectively, corresponding to the first engagement protrusions. It is formed so as to engage with the protrusion 37 and the second engagement protrusion 41.

Then, the feed screw is rotated in a predetermined direction by the drive of the electric motor to move the mounting base 19 to the lower right side shown in FIG. 4, and the injection nozzle 2 of the first injection unit 20 is moved.
0a is aligned with the first sprue 25b to operate the hydraulic cylinder 22 to move the injection nozzle 20a to the first sprue 25b.
After being pressed against b, the mold clamping cylinder 13 is operated to clamp the movable mold 12 and the fixed mold 25.

Next, the hydraulic cylinder 32 is operated to activate the second cylinder.
After the tip of the injection nozzle 31a of the injection unit 31 is brought into pressure contact with the second sprue 25c located on the mold matching surface between the movable mold 12 and the fixed mold 25 that have been clamped, the first injection unit 20 and the second injection unit 20 By simultaneously operating the injection unit 31 of the above, the synthetic resin melted in different colors is injected into the molding space 47 of the movable mold 12 and the fixed mold 25. At this time, the injection pressures of the first injection unit 20 and the second injection unit 31 are set so that the injection times of the movable mold 12 and the fixed mold 25 to reach the molding spaces are substantially equal to each other. The different colored synthetic resins thus injected are injected so as to meet at approximately the middle portion of the molding space.

As a result, the right half of the container 33 is colored by the color of the synthetic resin injected from the first injection unit 20, and the left half is colored by the color of the second injection unit 31. It is integrally formed.

In the above description, the first injection unit 20 is moved in the direction orthogonal to the machine center of the main body frame 3 so that the tip of the injection nozzle 20a is aligned with the first sprue 25b provided on the side of the fixed mold 25. However, as shown in FIG. 5, the first injection unit 51 may be fixed to the machine center of the main body frame 3 in a normal center injection mode to perform multicolor molding.

In this case, the first die provided on the fixed die 25
The sprue 25b is formed so as to extend from the machine center of the main body frame 3 to one side portion of the molding recess 25a, and its distance is longer than that of the second sprue 25c. In this case, the sprue 25b of the first injection unit 51 is The injection pressure is set to the second injection unit 3
By making the injection pressure higher than 1, the synthetic resins of different colors injected from the first injection unit 51 and the second injection unit 31 are merged at the central portion of the molding recess 25a, and thereby color coding is performed at the central portion. The molded container 33 can be molded.

The above description is based on the second injection unit 31.
The injection nozzle 31a of the second injection unit 31a of the second injection unit 31, as shown in FIG. 6, is used as the injection nozzle 31a of the second injection unit 31 as shown in FIG. Alternatively, a method may be used in which the sprue 25d provided on the side surface of the fixed mold 25 is brought into pressure contact with the sprue 25d and ejected from a direction orthogonal to the machine center. The multicolor molding method shown in FIG. 6 is a method in which the sprue provided on the side surface of the movable mold is brought into pressure contact with the injection nozzle of the second injection unit to inject from a direction orthogonal to the machine center. Of course, it is also good.

Furthermore, by appropriately adjusting the injection pressure of the first injection unit 20 and the second injection unit 31 and the position of the first sprue 25b in the fixed mold 25, the appropriate proportion of the container 33 can be moved to the first position. The synthetic resin of the color injected from the injection unit 20 of
It may be integrally molded with a synthetic resin of a color injected from the injection unit 31.

Furthermore, in the above description, the first and second synthetic resins of different colors are injected from the respective injection units, but in the method of the present invention, the first and second injection units are different. A method of injecting different kinds of synthetic resins and integrally molding a molded article made of different synthetic resins may be used.

[0036]

Therefore, according to the present invention, the second injection unit is arranged in the conventional molding machine without using a dedicated molding machine to integrally mold the molded products with the synthetic resins of different colors or kinds. Thus, it is possible to provide a multicolor molding method capable of avoiding an increase in the cost of the molding machine and reducing the molding cost.

Further, the present invention can provide a multi-color molding method capable of integrally molding a molded product having a good appearance by reducing the degree of color mixing at the boundary where synthetic resins of different colors or types merge. Is.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an apparatus embodying a multicolor molding method.

FIG. 2 is a schematic central cross-sectional view of separated dies.

FIG. 3 is a perspective view showing a molded product.

FIG. 4 is a schematic sectional view showing a multicolor molding state.

FIG. 5 is a central cross-sectional view of a mold showing a modified example of the present invention.

FIG. 6 is a central cross-sectional view of a mold showing a modified example of the present invention.

[Explanation of symbols]

 1 Molding Machine 12 Movable Mold 20 First Injection Unit 25 Fixed Mold 31 Second Injection Unit 33 Container as Molded Product 47 Molding Space

Claims (2)

[Claims] 1. The first synthetic resin is machine-centered by a first injection unit having an axis in a direction coinciding with the machine center of the molding machine, in the molding spaces of the fixed mold and the movable mold that have been clamped. And a second injection unit having an axis in a direction orthogonal to the machine center causes a second synthetic resin different from the first synthetic resin from the direction orthogonal to the machine center at a predetermined timing and A multi-color molding method characterized by integrally molding color-coded molded products by injecting each with injection pressure. 2. The multicolor molding according to claim 1, wherein the first injection unit is arranged so as to be movable in a direction orthogonal to the machine center of the molding machine, and can be aligned with a gate provided on a side portion of the fixed mold. Method.